LWUIT Resource problem

Hello all
I am using LWUIT and trying out the resource files to my theme i got the following mesage.
It was working before, but i didnt know what i did.

"java.lang.NullPointerException
at java.io.DataInputStream.read(DataInputStream.java:83)
at java.io.DataInputStream.readUnsignedShort(+4)
at java.io.DataInputStream.readShort(+4)
at com.sun.lwuit.util.Resources.openFile(Resources.java:134)
at com.sun.lwuit.util.Resources.<init>(Resources.java:114)
at com.sun.lwuit.util.Resources.open(Resources.java:449)
at com.telnet.HelloMidlet.startApp(HelloMidlet.java:30)
at javax.microedition.midlet.MIDletProxy.startApp(MIDletProxy.java:44)
at com.sun.midp.midlet.Scheduler.schedule(+270)
at com.sun.midp.main.Main.runLocalClass(+28)
at com.sun.midp.main.Main.main(+80)
java.io.IOException at javax.microedition.lcdui.ImmutableImage.getImageFromStream(Image.java:968)
at javax.microedition.lcdui.ImmutableImage.<init>(Image.java:939)
at javax.microedition.lcdui.Image.createImage(Image.java:313)
at com.sun.lwuit.impl.midp.GameCanvasImplementation.createImage(GameCanvasImplementation.java:584)
at com.sun.lwuit.Image.createImage(Image.java:428)
at hello.MyForm.<init>(MyForm.java:38)
at com.telnet.HelloMidlet.startApp(HelloMidlet.java:36)
at javax.microedition.midlet.MIDletProxy.startApp(MIDletProxy.java:44)
at com.sun.midp.midlet.Scheduler.schedule(+270)
at com.sun.midp.main.Main.runLocalClass(+28)
at com.sun.midp.main.Main.main(+80)
"